i'm contessa brewer. when you attend a fireworks display, you expect fireworks but not like this. what went wrong? in southeastern pennsylvania, a holiday celebration goes from festive to fearsome in the blink of an eye. >> oh, my god. >> what the -- what the -- >> july 4th, 2010, the town is celebrating more than american independence. they are also celebrating their home town's big birthday. lifelong natives look forward to the evening festivities. palmyra was celebrating and it was a big deal for the